The present invention relates to printing systems, and more particularly, to printing systems that make use of ink container vessels for delivery of ink to printing delivery systems.
Printing systems, such as ink-jet printing systems, typically use ink container vessels. Most ink container vessels used in popular printing systems today deploy some type of sold material within their reservoirs such as porous material or collapsible film. The porous material and/or collapsible films are used in the vessel containers to provide a means of preventing ink from leaking out of vents in the containers and to provide backpressure for the ink delivery system. These solid parts also prevent spillage of ink through vent holes of the container vessels during shipment and handling of them.
Such ink container vessels are typically purchased pre-filled with ink and are discarded after they run out of available ink. A serious drawback of such vessels, however, is that they often strand between 15% and 50% of their initial total fill of ink after depleting available ink for the printing system. xe2x80x9cStrandxe2x80x9d means that ink remains in the container vessels when they are discarded, because the ink cannot be accessed by the printing system. In other words, most current ink container vessels permanently leave behind up to half their initial volume of total ink in the vessel when the container needs to be discarded. Ink becomes trapped and lodged in nooks of the container to become permanently stranded and/or becomes trapped in porous materials used inside a vessel to retain the ink.
Moreover, volumetric efficiency of an ink supply container vessel suffers because of the presence of solid materials throughout the reservoir of a vessel. Such solid parts fill volume that may otherwise be used to store ink. Additionally, printer manufacturers often construct ink container vessels with larger volumetric ink capacities in order to compensate for the stranding of large percentages of ink. Unfortunately, larger vessels also increase the total size of printer products, because printer systems must be able to accommodate these larger vessels. Larger vessels also require higher initial fill volumes of ink, which is costly.
Furthermore, many current ink container vessels are also environmentally unfriendly; because they often cannot be easily recycled due to the amount of stranded ink left in the vessels once they have to be discarded (i.e., once there is no available ink for printing).
Still another problem associated with many current ink container vessels is the fluctuation of pressures within the container""s reservoir. It is common for ink container vessels to be exposed to temperature and altitude variations, which causes air volume within the reservoir to expand or contract. Such pressure variations have a negative impact on ink delivery systems, because it skews the consistency of ink flow delivered to printing media. Air expansion in a closed ink container may cause ink to be pushed out of the ink delivery system forcing ink to leak out of the system. Vessels that use solid materials in the reservoir impart flow restrictions on ink (in addition to trapping ink as described above), which also affects the quality of ink delivery systems and limits the types of ink delivery systems that can be used in combination with such vessels.
Exemplary embodiments of the present invention comprise high volumetric efficient free-ink container vessels. The vessels include a reservoir to store a supply of ink. A vent hole in the reservoir links atmospheric air to the reservoir. A mechanical vent system selectively opens and closes the vent hole in the reservoir. The mechanical vent system is equipped with a movable member that moves between a closed position covering the vent hole and an open position uncovering the vent hole. The mechanical vent system moves the movable member to open and close the vent hole. When the vent hole is open, non-atmospheric pressures imparted within the reservoir can be virtually eliminated by the exemplary mechanical vent system.
The exemplary high volumetric efficiency ink container described herein, therefore, introduces the broad concept of employing a mechanical vent system that imposes no pressure effects on the ink delivery system. The vent system is able to open the supply of air to the interior of the vessel when the vessel is inserted into the printer and close the supply of air when removed from the printer. Additionally, the vent system is able to open/close the vent hole at prescribed times. The exemplary high volumetric efficiency ink container of the present invention also allows positioning of the fluid interconnect port at substantially the lowest point of fluid reservoir, resulting in only a small residual portion of ink being stranded in ink container vessels when the ink supply is depleted. Furthermore, the vessel may be used with a wide variety of ink delivery systems, since there are no pressurized effects caused by the vessel.